Travel trailers have gained widespread popularity. Americans frequently take their summer vacations on the road, and enjoy the comfort of living and sleeping in a trailer home when not driving with the trailer in tow. However, unlike a house mounted on a concrete slab or rigid foundation, persons in the trailer can experience a certain queasiness or disruptions in their activities and comfort because the trailer is constantly shaking.
A prior art stabilizer for use on a travel trailer is shown in FIG. 1, and consists of two extensible braces mounted in canisters that are integrated into the structure of the trailer at the front corners. The braces are operated to extend to the ground and lock when the trailer is stationary, and are retractable for moving the trailer.
This system is generally unsatisfactory in dampening trailer oscillations such as caused by the movement of a person in the trailer, and fails to address the role of tire flex, particularly sidewall tire flex, in allowing trailer oscillations. Generally the suspension and leaf springs will be stiffer than the tires, pointing to the tires as the primary source of the unwanted motion. Trailer body frames are not perfectly stiff, and various end braces are inadequate in suppressing swaying motions, side to side motions of the rear of the trailer (as in a fishtailing motion) or up and down motions (as in a front-to-rear bouncing motion or a centerbeam flexion motion) on the flexible sidewalls of the tires, which have not previously been recognized as being a primary source of unwanted trailer motion.
Other art of general relevance is found in U.S. Pat. Nos. 3,690,694, 3,801,128 and 3933372 to Herndon. The system taught by Herndon does not allow setting the leg length independently, which is a disadvantage when the trailer is on uneven ground, and attempts to stabilize only the rear of the trailer and not the frame of the trailer at the axle. Tension is applied by cinching together contralateral legs with a cross tie bar, but the cinching mechanism would require crawling under the trailer if adapted to the center axle. Thus the art fails to recognize a key aspect of the problem that needs to be addressed to be successful and cannot readily be adapted for a center axle. Similarly, U.S. Pat. No. 3,642,242 to Danekas, U.S. Pat. No. 3,558,092 to Hanson, and U.S. Pat. No. 7,338,052 to Hanscomb focus on the ends of the trailer, not the center axle, again, for more than fifty years, not recognizing the problem as one of stabilizing tire sidewall-related oscillations.
Because trailer oscillation is unpleasant, can interfere with eating or sleeping and distract from the comfort of living in a travel trailer or trailer-mounted mobile home, there is a long felt but unsolved need for a new and improved system to suppress them.